81542248099 has 8 divisors (see below), whose sum is σ = 89471611152. Its totient is φ = 73849582560.

The previous prime is 81542248097. The next prime is 81542248153. The reversal of 81542248099 is 99084224518.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81542248099 - 2¹ = 81542248097 is a prime.

It is a super-2 number, since 2×81542248099² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81542248097) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59173657 + ... + 59175034.

It is an arithmetic number, because the mean of its divisors is an integer number (11183951394).

Almost surely, 2^81542248099 is an apocalyptic number.

81542248099 is a deficient number, since it is larger than the sum of its proper divisors (7929363053).

81542248099 is a wasteful number, since it uses less digits than its factorization.

81542248099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118348757.

The product of its (nonzero) digits is 1658880, while the sum is 52.

The spelling of 81542248099 in words is "eighty-one billion, five hundred forty-two million, two hundred forty-eight thousand, ninety-nine".